The safety of passengers and drivers in motor vehicle accidents depends in large part on the construction and performance of energy absorbing components within the vehicle's body. These components are designed to absorb the impact energy of a collision, and to prevent the transfer of that impact energy to the occupant of the vehicle. The official gazette of Japanese Patent No. 3,313,999, Publication Number 10-250513, issued to KYORAKU CO. LTD. and NAGASE & CO. LTD., which is hereby incorporated in its entirety for all purposes, discloses one such component having a hollow double wall structure, produced by blow molding of thermoplastics, and having recessed ribs from the front surface wall and the rear surface wall with the top end parts thereof bonded with each other so as to be integrated for improving the energy absorbing property.
Since this kind of the energy absorbing member for a vehicle is to be disposed inside a vehicle constituent member such as a door and a body side panel, the dimensions of the component are dependant on the size of the cavity available. When the dimensions of the component are such that the ribs become elongate, as is illustrated in FIG. 33 of the present invention, the thickness of the walls of the rib becomes reduced as the parison becomes stretched too thin. This reduction in thickness reduces the strength of the rib and the ability of the rib to absorb impact energy.